Led lamp with a sleeve located in heat sink

ABSTRACT

An LED lamp includes: a lamp shell; a passive heat dissipating element; a power source; a light emitting surface comprising LED chips; a first heat dissipating channel; a second heat dissipating channel; and a lamp cover having a light output surface and an end surface, wherein the end surface is formed with a vent; wherein the first heat dissipating channel comprises a first end and a second end; wherein the second heat dissipating channel comprises a third end; wherein the first end is projected onto the end surface in an axis of the LED lamp to occupy an area on the end surface, which is defined as a first portion, another area on the end surface is defined as a second portion, and the vent in the first portion is greater than the vent in the second portion in area.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 16/267,747 filed on Feb. 5, 2019, which claims priority to thefollowing Chinese Patent Applications No. CN 201810130085.3 filed onFeb. 8, 2018, CN 201810479044.5 filed on Mar. 18, 2018, CN201810523952.X filed on May 28, 2018, CN 201810573322.3 filed on Jun. 6,2018, CN 201810634571.9 filed on Jun. 20, 2018, CN 201810763800.7 fieldon Jul. 12, 2018, CN 201810763089.5 filed on Jul. 12, 2018, CN201810972904.9 filed on Aug. 24, 2018, CN 201811172470.0 filed on Oct.9, 2018, CN 201811295618.X filed on Nov. 1, 2018, CN 201811299410.5filed on Nov. 2, 2018, CN 201811347198.5 filed on Nov. 13, 2018, CN201811378174.6 filed on Nov. 19, 2018, and CN 201811466198.7 filed onDec. 3, 2018, the disclosures of which are incorporated herein in theirentirety by reference.

FIELD OF THE INVENTION

The invention relates to lighting, particularly to LED lamps with asleeve located in heat sink.

BACKGROUND OF THE INVENTION

Because LED lamps possess advantages of energy saving, high efficiency,environmental protection and long life, they have been widely adopted inthe lighting field. For LED lamps used as an energy-saving green lightsource, a problem of heat dissipation of high-power LED lamps becomesmore and more important. Overheating will result in attenuation oflighting efficiency. If waste heat from working high-power LED lampscannot be effectively dissipated, then the life of LED lamps will bedirectly negatively affected. As a result, in recent years, solution ofthe problem of heat dissipation of high-power LED lamps is an importantissue for the industry.

OBJECT AND SUMMARY OF THE INVENTION

The LED lamp described in the present disclosure includes an LED (lightemitting diode) lamp comprising: a lamp shell including a lamp head, alamp neck and a sleeve, the lamp head connects to the lamp neck whichconnects to the sleeve; a passive heat dissipating element having a heatsink connected to the lamp shell, wherein the heat sink comprises finsand a base, the sleeve of the lamp shell is located in the heat sink,the lamp neck projects from the heat sink, height of the lamp neck is atleast 80% of height of the heat sink, the heat sink comprises first finsand second fins, bottoms of both the first fins and the second fins inan axis of the LED lamp connect to the base, the first fins interlacewith the second fins at regular intervals, and one of the second finsincludes a third portion and two fourth portions, the two fourthportions are symmetrical about the third portion; a power source havinga first portion and a second portion, wherein the first portion of thepower source is disposed in both the lamp neck and the lamp head of thelamp shell, and the second portion of the power source is disposed inthe heat sink of the passive heat dissipating element; a light emittingsurface connected to the heat sink of the passive heat dissipatingelement and comprising LED chips electrically connected to the powersource, wherein the light emitting surface and the heat sink areconnected to form a heat transferring path from the LED chips to thepassive heat dissipating element; a first heat dissipating channelformed in a chamber of the lamp shell for dissipating heat generatedfrom the power source while the LED lamp is working, and the chamber islocated between the bottom of the LED lamp and the upper portion of thelamp neck; a second heat dissipating channel formed in the heat sink andbetween the fins and the base for dissipating the heat generated fromthe LED chips and transferred to the heat sink; and a lamp coverconnected with the heat sink and having a light output surface and anend surface, wherein the end surface is formed with a vent to let airflowing from outside of the LED lamp into both the first heatdissipating channel and the second heat dissipating channel through thevent; wherein the first heat dissipating channel comprises a first endon the light emitting surface to allow air flowing from outside of theLED lamp into the chamber, and a second end on the upper portion of thelamp neck of the lamp shell to allow air flowing from inside of thechamber out to the LED lamp; wherein the second heat dissipating channelcomprises a third end on the light emitting surface to allow air flowingfrom outside of the LED lamp into the second heat dissipating channel,and flowing out from spaces between every adjacent two of the fins;wherein the light emitting surface further comprises an apertureconfigured to simultaneously communicate with both the first end of thefirst heat dissipating channel and the third end of the second heatdissipating channel, the aperture is located in a central region of thelight emitting, and the aperture forms an air intake of both the firstheat dissipating channel and the second heat dissipating channel;wherein the heat sink is disposed outwardly of the sleeve, and thesecond portion of the power source is disposed in the inner space of thesleeve, the second portion of the power source and the heat sink of thepassive heat dissipating element are insulated through the sleeve toprevent heat from the heat sink from affecting the power source in thesleeve; wherein the first end is projected onto the end surface in anaxis of the LED lamp to occupy an area on the end surface, which isdefined as a first portion, another area on the end surface is definedas a second portion, and the vent in the first portion is greater thanthe vent in the second portion in area.

Preferably, a distance is kept between distal ends of the fins and thesleeve, and air exists in the distance between the fins and the sleeveof the lamp shell.

Preferably, part of the fins are in contact with an outer surface of thesleeve.

Preferably, the first end on the light emitting surface is formed withan air inlet, the air inlet is located in a lower portion of the heatsink and radially corresponds to an inner side or the inside of the heatsink.

Preferably, the sleeve has an upper portion and a lower portion, theupper portion is connected to the lower portion through an air guidingsurface, a diameter of cross-section of the air guiding surface downwardtapers off along the axis of the LED lamp.

Preferably, the sleeve includes a first portion and a second portion inthe axial direction, the second portion is a part of the sleeve belowthe air guiding surface, electronic components of the power source,which are located in the second portion of the sleeve, includeelectrolytic capacitors.

Preferably, the second end on the upper portion of the lamp neck of thelamp shell is formed with a venting hole, the lamp shell has an airflowlimiting surface which extends radially outwardly and is located awayfrom the venting hole, the airflow limiting surface cloaks at least partof the fins.

Preferably, upper portions of at least part of the fins in the axialdirection of the LED lamp correspond to the airflow limiting surface.

Preferably, an outer wall of the sleeve is provided with a passage tomake part of convection air pass through the passage to reach the heatsink.

Preferably, the power source includes a heat-generating element, theheat-generating element is in contact with the lamp head through athermal conductor and the heat-generating element is fastened to thelamp head through the thermal conductor.

Preferably, the lamp head includes a metal portion, at least part of aninner side of the metal portion constitutes a wall of the inner chamberof the lamp shell to make the thermal conductor directly connecting withthe metal portion and performing heat dissipation by the metal portion

Preferably, all the electrolytic capacitors are disposed in the sleeve.

Preferably, at least one of the electronic components of the powersource, which is the most adjacent to the first end of the first heatdissipating channel is one of the electrolytic capacitors.

Preferably, at least part of the electrolytic capacitor which is themost adjacent to the first end of the first heat dissipating channelexceeds the power board in the axial direction of the LED lamp.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed descriptions, given by way of example, and notintended to limit the present invention solely thereto, will be best beunderstood in conjunction with the accompanying figures:

FIG. 1 is a structural schematic view of one embodiment of an LED lampaccording to aspects of the invention;

FIG. 2 is a schematic cross-sectional view of the LED lamp of FIG. 1;

FIG. 3 is an exploded view of the LED lamp of FIG. 1;

FIG. 4 is a schematic cross-sectional view of the LED lamp of FIG. 1,which shows the first heat dissipating channel and the second heatdissipating channel;

FIG. 5 is a perspective view of the LED lamp of FIG. 1;

FIG. 6 is a structural schematic view of FIG. 5 without the light outputsurface;

FIG. 7 is a cross-sectional view of another embodiment of the LED lampaccording to aspects of the invention, which shows the flat light outputsurface;

FIG. 8 is a schematic view of an end surface of the lamp cover of anembodiment;

FIGS. 9A˜9G are schematic views of some embodiments of the lamp cover;

FIG. 10 is a perspective view of an LED lamp, according to anotherembodiment of the present invention;

FIG. 11 is a cross-sectional view of the LED lamp of FIG. 10;

FIG. 12 is a top view of the heat sink of the LED lamp of FIG. 10;

FIG. 13 is an enlarged view of portion E in FIG. 12;

FIG. 14 is a schematic view showing a vortex formed by air near thesecond fins according to another embodiment of the present invention;

FIG. 15 is a partially schematic view of the heat sink of anotherembodiment;

FIG. 16 is a bottom view of the LED lamp of FIG. 1 without the lampcover;

FIG. 17 is an enlarged view of portion A in FIG. 16;

FIG. 18 is a cross-sectional view of an LED lamp, according to anotherembodiment of the present invention;

FIGS. 19A˜19C are perspective views of the power source, according tosome embodiments of the present invention;

FIG. 19D is a main view of the power source of the embodiment of FIGS.19A˜19C;

FIG. 20 is an enlarged view of portion B in FIG. 2;

FIG. 21 is a partially schematic view of an LED lamp;

FIG. 22 is a cross-sectional view of the LED lamp of another embodiment;

FIG. 23 is a schematic view of an arrangement of the convection channelsof the LED lamp of FIG. 22;

FIG. 24 is a block diagram of the power module of an embodiment of theinvention;

FIG. 25 is a circuit diagram of an EMI reduction circuit of anembodiment of the invention;

FIG. 26 is a circuit diagram of a rectifier and a filter of anembodiment of the invention;

FIG. 27 is a circuit diagram of a PFC of an embodiment of the invention;

FIG. 28 is a circuit diagram of a power converter of an embodiment ofthe invention;

FIG. 29 is a circuit diagram of a bias generator of an embodiment of theinvention;

FIG. 30 is a circuit diagram of a bias generator of another embodimentof the invention;

FIG. 31 is a circuit diagram of a temperature detector of an embodimentof the invention; and

FIG. 32 is a circuit diagram of a temperature compensator of anembodiment of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

To make the present invention understandable and readable, the followingdisclosure will now be described in the following embodiments withreference to the drawings. The following descriptions of variousembodiments of this invention are presented herein for purpose ofillustration and giving examples only. It is not intended to beexhaustive or to be limited to the precise form disclosed.

FIG. 1 is a structural schematic view of an embodiment of an LED lampaccording to certain aspects of the invention. FIG. 2 is a schematiccross-sectional view of the LED lamp of FIG. 1. FIG. 3 is an explodedview of the LED lamp of FIG. 1. As shown in the figures, the LED lampincludes a heat sink 1, a lamp shell 2, a light board 3, a lamp cover 4and a power source 5. In this embodiment, the light board 3 is connectedto the heat sink 1 by attachment for rapidly transferring heat from thelight board 3 to the heat sink 1 when the LED lamp is working. In someembodiments, the light board 3 is riveted to the heat sink 1. In someembodiments, the light board 3 is screwed to the heat sink 1. In someembodiments, the light board 3 is welded to the heat sink 1. In someembodiments, the light board 3 is adhered to the heat sink 1. In thisembodiment, the lamp shell 2 is connected to the heat sink 1, the lampcover 4 covers the light board 3 to make light emitted from the lightboard 3 pass through the lamp cover to project out. The power source 5is located in a chamber of the lamp shell 2 and the power source 5 is ECto the LED chips 311 for providing electricity.

FIG. 4 is a schematic cross-sectional view of the LED lamp. As shown inFIGS. 2 and 4, the chamber of the lamp shell 2 of this embodiment isformed with a first heat dissipating channel 7 a. An end of the firstheat dissipating channel is formed with a first air inlet 2201. Anopposite end of the lamp shell 2 is formed with a venting hole 222 (atan upper portion of the lamp neck 22). Air flows into the first heatdissipating channel 2201 and flows out from the venting hole 222 forbringing out heat in the first heat dissipating channel 7 a (primarily,heat of the working power source 5). As for the path of heatdissipation, heat generated from the heat-generating components of theworking power source 5 is transferred to air (around the heat-generatingcomponents) in the first heat dissipating channel 7 a by thermalradiation first, and then external air enters the first heat dissipatingchannel 7 a by convection to bring out internal air to make heatdissipation.

As shown in FIGS. 1, 2 and 4, a second heat dissipating channel 7 b isformed in the fins and the base 13 of the heat sink 1. The second heatdissipating channel 7 b has a second air inlet 1301. In this embodiment,the first air inlet 2201 and the second air inlet 1301 share the sameopening formed on the light board 3. This will be described in moredetail later. Air flows from outside of the LED lamp into the second airinlet 1301, passes through the second heat dissipating channel 7 b andfinally flows out from spaces between the fins 11 so as to bring outheat of the fins 11 to enhance heat dissipation of the fins 11. As forthe path of heat dissipation, heat generated from the LED chips isconducted to the heat sink 1, the fins 11 of the heat sink 1 radiate theheat to surrounding air, and convection is performed in the second heatdissipating channel 7 b to bring out heated air in the heat sink 1 tomake heat dissipation.

As shown in FIGS. 1 and 4, the heat sink 1 is provided with a third heatdissipating channel 7 c formed between adjacent two of the fins 11 or ina space between two sheets extending from a single fin 11. A radialouter portion between two fins 11 forms an intake of the third heatdissipating channel 7 c. Air flows into the third heat dissipatingchannel 7 c through the radial outer portion of the LED lamp to bringout heat radiated from the heat sink 11 to air.

FIG. 5 is a perspective view of the LED lamp of an embodiment, whichshows assembling of the heat sink 1 and the lamp cover 4. FIG. 6 is astructural schematic view of FIG. 5 without the light output surface 43.As shown in FIGS. 5 and 6, in this embodiment, the lamp cover 4 includesa light output surface 43 and an end surface 44 with a vent 41. Airflows into both the first heat dissipating channel 7 a and the secondheat dissipating channel 7 b through the vent 41. When the LED chips 311(shown in FIG. 6) are illuminated, the light passes through the lightoutput surface 43 to be projected from the lamp cover 4. In thisembodiment, the light output surface 43 may use currently availablelight-permeable material such as glass, PC, etc. The term “LED chip”mentioned in all embodiments of the invention means all light sourceswith one or more LEDs (light emitting diodes) as a main part, andincludes but is not limited to an LED bead, an LED strip or an LEDfilament. Thus, the LED chip mentioned herein may be equivalent to anLED bead, an LED strip or an LED filament.

As shown in FIGS. 5 and 6, in this embodiment, an inner reflectingsurface 4301 is disposed inside the light output surface 43 of the lampcover 4. The inner reflecting surface 4301 is disposed in the innercircle of the array of LED chips 311. In an embodiment, an outerreflecting surface 4302 is disposed in the outer circle of the array ofLED chips 311. The outer reflecting surface 4302 corresponds to the LEDchips 311 on the light board 3. The arrangement of both the innerreflecting surface 4301 and the outer reflecting surface 4302 is usedfor adjusting a light emitting range of the LED chip set 31 to make thelight concentrated and to increase brightness in a local area. Forexample, under the condition of the same luminous flux, illuminance ofthe LED lamp can be increased. In one example, all the LED chips 311 inthis embodiment are mounted on the bottom side of the light board 3 (ina using status). In this embodiment, the LED lamp of the presentembodiment do not emit lateral light from the LED chips 311. Whenworking, the primary light emitting surfaces of the LED chips 311 arecompletely downward. At least 60% of the light from the LED chips 311are emitted through the light output surface 43 without reflection. As aresult, in comparison with those LED lamps with lateral light (thelateral light is reflected by a cover or a lampshade to be emitteddownward, and in theory there must be part of light loss in the processof reflection.) The LED chips 311 in this embodiment possess betterlight emitting efficiency. In one example, under the condition of thesame lumen value (luminous flux), the LED lamp in the present embodimentpossesses higher illuminance. And the emitted light can be concentratedto increase illuminance in a local area by the arrangement of both theinner reflecting surface 4301 and the outer reflecting surface 4302, forexample, in an area under the LED lamp between 120 degrees and 130degrees (a light emitting range under the LED lamp between 120 degreesand 130 degrees). When the LED lamp is installed at a relatively highposition, in the same angular range of light emitting, the lit area ofthe LED lamp still satisfies the requirement and illuminance in thisarea can be higher.

The inner reflecting surface 4301 is used for reflecting part of lightemitted from the innermost LED chips 311 of the LED chip set 31. Theouter reflecting surface 4302 is used for reflecting part of lightemitted from the outermost LED chips of the LED chipset 31. Theoutermost LED chips 311 are greater than the innermost LED chips 311 innumber. The outer reflecting surface 4302 is greater than the innerreflecting surface 4301 in area. Because the outermost portion of theLED chip set 31 includes more LED chips than the innermost portion,larger reflecting area is beneficial to regulate light output.

FIG. 8 is a schematic view of an end surface 44 of the lamp cover 4 ofan embodiment. As shown, the ratio of a total of cross-sectional area ofthe vent 41 to overall area of the end surface 44 (area of a single sideof the end surface 44, such as the side away from the LED chips 311) is0.01˜0.7. Preferably, the ratio of a total of cross-sectional area ofthe vent 41 to overall area of the end surface 44 is 0.3˜0.6. Morepreferably, the ratio of a total of cross-sectional area of the vent 41to overall area of the end surface 44 is 0.4˜0.55. By limiting the ratioof a total of cross-sectional of the vent 41 to overall area of the endsurface 44 to the above ranges, not only can air intake of the vent 41be guaranteed, but also adjustment of area of the vent 41 is implementedunder ensuring structural strength of the end surface 44. When the ratioof area of the vent 41 to area of the end surface 44 is 0.4˜0.55, notonly can air intake of the vent 41 be guaranteed to satisfy requirementsof heat dissipation of the LED lamp, but also the vent 41 does notaffect structural strength of the end surface 44 to prevent the endsurface 44 with the vent 41 from being fragile due to collision orpressure.

As shown in FIG. 8, a diameter of a maximum inscribed circle of the vent41 is less than 2 mm, preferably, 1.0˜1.9 mm. As a result, both bugs andmost dust can be resisted, and venting efficiency of the vent 41 can bekept great enough. In one example, alternatively, the vent 41 definesboth a length direction and a width direction, i.e. the vent has alength and a width, and the length is greater than the width. Thelargest width of inscribed circle of the vent 41 may be less than 2 mm.In an embodiment, the largest width is from 1 mm to 1.9 mm. In addition,the largest width of the vent 41 may be greater than 1 mm. If the widthof the vent 41 is less than 1 mm, then more pressure is required to pushair to enter the vent 41, which is advanced for venting.

FIGS. 9A˜9G show shapes of some embodiments of the vent 41. As shown inFIGS. 9A-9G, the vent 41 may be circular, strip-shaped, arced,trapezoidal, diamond or their combination. As shown in FIG. 9A, when thevent 41 is configured to be circular, its diameter should be less than 2mm to resist bugs and most dust and venting efficiency of the vent 41can be kept great enough. As shown in FIGS. 9B and 9C, when the vent 41is configured to be strip-shaped or arced, its width should be less than2 mm to accomplish the above effects. As shown in FIG. 9D, when the vent41 is configured to be trapezoidal, its lower base should be less than 2mm to accomplish the above effects. As shown in FIG. 9E, when the vent41 is configured to be round-cornered rectangular, its width should beless than 2 mm to accomplish the above effects. As shown in FIGS. 9F and9G, when the vent 41 is configured to be triangular or drop-shaped, adiameter of its maximum inscribed circle should be less than 2 mm.

In some embodiments, the vent 41 on the end surface 44 is multiple innumber. For example, the vents 41 may be annularly arranged on the endsurface 44 for even air intake. The vents 41 may also be radiallyarranged on the end surface 44. The vents 41 may also be irregularlyarranged.

In FIG. 9A, there are two broken lines on the end surface 44. The innerbroken line represents a position the first air inlet 2201 (as shown inFIG. 2) is projected onto the end surface 44. The region within theinner broken line is defined as a first portion (first opening region433). The region between the inner circle and the outer circle isdefined as a second portion (second opening region 434). In thisembodiment, the first air inlet 2201 is projected onto the end surfacein an axis of the LED lamp to occupy an area on the end surface 44, itis the first portion (first opening region 433). The other area on theend surface 44 is the second portion (second opening region 434). Thevent 41 in the first portion is greater than the vent 41 in the secondportion in area. Such an arrangement is advantageous to making most airflow into the first heat dissipating channel 7 a for better effect ofheat dissipation to the power source 5 and reduction of rapidly aging ofelectronic components of the power source 5. These features are alsoavailable to the vent 41 in other embodiments.

In other embodiments, the first air inlet 2201 is projected onto the endsurface 44 in an axis of the LED lamp to occupy an area on the endsurface 44, which may be a first portion (first opening region 433). Theother area on the end surface 44 may be a second portion (second openingregion 434). The vent 41 in the first portion is smaller than the vent41 in the second portion in area. As a result, heat of the fins 11 canbe better dissipated to perform better heat dissipation to the LED chips311 and prevent a region around the LED chips 311 from forming hightemperature. In detail, area of both the first portion and the secondportion can be selected according to actual requirements.

In some applications, there may be a limit of overall weight of an LEDlamp. For example, when an LED lamp adopts an E39 head, its maximumweight limit is 1.7 Kg. Thus, besides the fundamental elements such as apower source, a lamp cover and a lamp shell, in some embodiments, weightof a heat sink is limited within 1.2 Kg. For some high-power LED lamps,the power is about 150 W˜300 W, and their luminous flux can reach 20000lumens to 45000 lumens. Under a limit of weight, a heat sink shoulddissipate heat from an LED lamp with 20000˜45000 lumens. Under acondition of heat dissipation of natural convection, usually power of 1W needs area of heat dissipation of at least 35 square cm. The followingembodiments intend to reduce area of heat dissipation for power of 1 Wunder guarantee of a receiving space of the power source 5 and effect ofheat dissipation. Under a precondition of weight limit of the heat sink1 and limit of the power source 5, the best effect of heat dissipationcan be accomplished.

As shown in FIGS. 1 and 2, in this embodiment, the LED lamp includespassive heat dissipating elements which adopt natural convection andradiation as a heat dissipating manner without any active heatdissipating elements such as a fan. The passive heat dissipating elementin this embodiment includes a heat sink 1 composed of fins 11 and a base13. The fins 11 radially extend from and connect to the base 13. Whenusing the LED lamp, at least part of heat from the LED chips 311 isconducted to the heat sink 1 by thermal conduction. At least part ofheat occurring from the heat sink 1 is transferred to external air bythermal convection and radiation.

As shown in FIGS. 2, 4 and 5, a gap is kept between the end side 44 andthe light board 3 to form a room 8. The room 8 communicates with boththe first air inlet 2201 of the first heat dissipating channel 7 a andthe second air inlet 1301 of the second heat dissipating channel 7 b.Air flows into the room 8 through the vent 41 of the end side 44 andthen flows into both the first heat dissipating channel 7 a and thesecond heat dissipating channel 7 b. The room 8 allows air therein tomix and the mixed air is distributed according to negative pressure(resulting from temperature difference) of both the first and secondheat dissipating channels 7 a, 7 b so as to make distribution of airmore reasonable.

FIG. 12 is top view of the heat sink 1 of the LED lamp of an embodiment.As shown, the heat sink 1 suffers the above volume limit, so at leastpart of the fins 11 are extended outward in a radial direction of theLED lamp with at least two sheets at an interval. By such anarrangement, the fins 11 in a fixed space can have larger area of heatdissipation. In addition, the extended sheets form support to the fins11 to make the fins firmly supported on the base 13 to prevent the fins11 from deflecting.

In detail, as shown in FIG. 12, the fins include first fins 111 andsecond fins 112. The bottoms of both the first fins 111 and the secondfins 112 in an axis of the LED lamp connect to the base 13. The firstfins 111 interlace with the second fins 112 at regular intervals. Beingprojected from the axial direction of the LED lamp, each of the secondfins 112 is to be seen as a Y-shape. Such Y-shaped second fins 112 canhave more heat dissipating area under a condition of the heat sink 1occupying the same volume. In this embodiment, both the first fins 111and the second fins are evenly distributed on a circumference,respectively. Every adjacent two of the second fins 112 are symmetricalabout one of the first fins 111. In this embodiment, an interval betweenone of the first fins 111 and adjacent one of the second fins 112 is8˜12 mm. In general, to make air flow in the heat sink 1 smooth and tomake the heat sink perform a maximum effect of heat dissipation,intervals between the fins 11 should be as uniform as possible.

As shown in FIGS. 6 and 12, at least one of the fins 11 is divided intotwo portions in a radial direction of the LED lamp. Thus, a gap betweenthe two portions forms a passage to allow air to pass. In addition, theprojecting area of the gap directly exactly corresponds to an area thatthe LED chips 311 are positioned on the LED board 3 to enhanceconvection and improve an effect of heat dissipation to the LED chips311. In an aspect of limited overall weight of the LED lamp, part of thefins 11 divided with a gap reduces the amount of the fins 11, decreasesoverall weight of the heat sink 1, and provides a surplus space toaccommodate other elements.

FIG. 13 is an enlarged view of portion E in FIG. 12. As shown in FIGS.12 and 13, the fins 11 includes first fins 111 and second fins 112. Eachof the first fins 11 is divided into two portions in a radial directionof the LED lamp, i.e. a first portion 111 a and a second portion 111 b.The two portions are divided with a gap portion 111 c. The first portion111 a is located inside the second portion 111 b in a radial direction.Each of the second fins 112 has a third portion 112 a and a fourthportion 112 b extending therefrom. The fourth portions 112 b are locatedradially outside the third portions 112 a to increase space utilizationand make the fins have more heat dissipating are for heat dissipation.As shown in FIG. 13, the third portion 112 a is connected to the fourthportion 112 b through a transition portion 113. The transition portion113 has a buffer section 113 a and a guide section 113 b. At least oneor both of the buffer section 113 a and the guide section 113 b arearced in shape. In other embodiment, both the buffer section 113 a andthe guide section 113 b are formed into an S-shape or an invertedS-shape. The buffer section 113 a is configured to prevent air radiallyoutward flowing along the second fins 112 from being obstructed to causevortexes. Instead, the guide section 113 b is configured to be able toguide convection air to radially outward flow along the second fins 112without interference (as shown in FIG. 14).

As shown in FIG. 13, one of the second fins 112 includes a third portion112 a and two fourth portions 112 b. The two fourth portions 112 b aresymmetrical about the third portion 112 a. In other embodiments, one ofthe second fins 112 may include a third portion 112 a and multiplefourth portions 112 b such as three or four fourth portions 112 b (notshown). The multiple fourth portions 112 b of the second fin 112 arelocated between two first fins 111.

As shown in FIG. 13, a direction of any tangent of the guide section 113b is separate from the gap portion 111 c to prevent convection air fromflowing into the gap portion 111 c through the guide portion 113 b, suchthat the poor efficiency of heat dissipation caused by longer convectionpaths is able to be avoid as well. Preferably, a direction of anytangent of the guide section 113 b is located radially outside the gapportion 111 c. In other embodiments, a direction of any tangent of theguide section 113 b is located radially inside the gap portion 111 c.

As shown in FIG. 15, in another embodiment, a direction of any tangentof the guide section 113 b falls in the gap portion 111 c to makeconvection more sufficient but convection paths will increase.

As shown in FIG. 10, at least partially of fin 11 has a protrusion 1102projecting from a surface of the fin 11. The protrusions 1102 extendalong an axis of the LED lamp and are in contact with the base 13. Asurface of the protrusion 1102 may selectively adopt a cylindrical shapeor a regular or an irregular polygonal cylinder. The protrusions 1102increase surface area of the fins 11 to enhance efficiency of heatdissipation. In addition, the protrusions 1102 also form a supporteffect to the fins 11 to prevent the fins 11 from being inflected inmanufacture. In some embodiments, a single fin 11 is divided into twoportions in a radial direction of the LED lamp. Each portion is providedwith at least one protrusion 1102 to support the two portions. In thisembodiment, the protrusion 1102 is located at an end portion of each fin11 in a radial direction of the LED lamp, for example, at end portionsof the first portions 111 a, 111 b (the ends near the gap portion 111c).

FIG. 16 is a bottom view of the LED lamp of FIG. 1 without the lampcover 4. FIG. 17 is an enlarged view of portion A in FIG. 16. As shownin FIGS. 16 and 17, the heat sink 1 is disposed outwardly of the sleeve21, and the power source 5 is disposed in the inner space of the sleeve21. A distance is kept between distal ends of the fins 11 and the sleeve21. Accordingly, the sleeve 21 which has been heated to be thermallyexpanded will not be pressed by the fins 11 to be damaged. Also, heatfrom the fins 11 will not be directly conducted to the sleeve 21 toadversely affect electronic components of the power source 5 in thesleeve 21. Finally, air existing in the distance between the fins 11 andthe sleeve 21 of the lamp shell 2 (as shown in FIG. 3) possesses aneffect of thermal isolation so as to further prevent heat of the heatsink 1 from affecting the power source 5 in the sleeve 21. In otherembodiments, to make the fins 11 have radial support to the sleeve 21,distal ends of the fins 11 may be in contact with an outer surface ofthe sleeve 21 and another part of the fins 11 are not in contact withthe sleeve 21. Such a design may be applied in the LED lamp shown inFIG. 16. As shown in FIG. 16, the light board 3 includes a thirdaperture 32 for exposing both the first air inlet 2201 of the first heatdissipating channel 7 a and the second air inlet 1301 of the second heatdissipating channel 7 b. In some embodiments, to rapidly dissipate heatfrom the power source 5, the ratio of cross-sectional area of the firstair inlet 2201 to cross-sectional area of the second air inlet 1301 isgreater than 1 but less than or equal to 2. In some embodiments, torapidly dissipate heat from the power source 5, the ratio ofcross-sectional area of the second air inlet 1301 to cross-sectionalarea of the first air inlet 2201 is greater than 1 but less than orequal to 1.5.

As shown in FIGS. 10 and 11, the innermost of the fins 11 in a radialdirection of the LED lamp is located outside the venting hole 222 in aradial direction of the LED lamp. In one example, an interval is keptbetween the innermost of the fins 11 in a radial direction of the LEDlamp and the venting hole 222 in a radial direction of the LED lamp. Asa result, heat from the fins 11 flowing upward will not gather to theventing hole 222 to keep an interval with the venting hole 222. Thisavoids heat making air around the venting hole 222 heat up to affectconvection temperature speed of the first heat dissipating channel 7 a(the convection speed depends upon a temperature difference between twosides of the first heat dissipating channel 7 a, when air temperaturenear the venting hole 222 rises, the convection speed willcorrespondingly slowdown.).

As shown in FIG. 16, in this embodiment, the light board 3 includes atleast one LED chip set 31 having LED chips 311.

As shown in FIGS. 6 and 16, in this embodiment, the light board 3 isdivided into three areas comprising an inner ring, a middle ring and anouter ring. All the LED chip sets 31 are located in the three areas. Inone example, the inner ring, the middle ring and the outer ring areseparately mounted by different amount of LED chip sets 31. In anotheraspect, the light board 3 includes three LED chip set 31. The three LEDchip sets 31 are respectively located in the inner ring, the middle ringand the outer ring. Each of the LED chip sets 31 separately in the innerring, the middle ring and the outer ring has at least one LED chip 311.

As shown in FIGS. 1 and 16, the light board 3 has an inner border 3002and an outer border 3003. Both the inner border 3002 and the outerborder 3003 separately upward extend along the axial direction of theLED lamp to form a region. An area of part of the fins 11 inside theregion is greater than an area of part of the fins 11 outside theregion. As a result, the most of the fins 11 can correspond to the lightboard 3 (a shorter heat dissipating path) to enhance heat dissipatingefficiency of the fins 11 and increase effective area of heat conductionof the fins 11 to the LED chips 311.

As shown in FIGS. 4 and 16, the light board 3 is formed with a thirdaperture 32 separately communicating with the first heat dissipatingchannel 7 a and the second heat dissipating channel 7 b. For example,the third aperture 32 communicates with spaces between the fins 11 andthe chamber of the lamp shell 2 to form air convection paths between thespaces between the fins 11 and between the chamber of the lamp shell 2and the outside of the Led lamp. The third aperture 32 is located insidethe inner ring of the LED lamp. Thus, it would not occupy the space ofthe reflecting region 3001 to affect reflective efficiency. In detail,the third aperture 32 is located at a central region of the light board3 and both the first air inlet 2201 and the second air inlet 1301 makeair intake through the same aperture (the third aperture 32). In oneexample, after convection air passes through the third aperture 32, andthen enters the first air inlet 2201 and the second air inlet 1301. Thethird aperture 32 is located at a central region of the light board 3,so both the first air inlet 2201 and the second air inlet 1301 cancommonly use the same air intake. Thus, this can prevent occupying anexcessive region of the light board 3 and prevent the usable regionalarea of the light board 3 for disposing the LED chips 311 fromdecreasing due to multiple air intakes. On the other hand, the sleeve 21corresponds to the third aperture 32, so convection air may have aneffect of thermal isolation to prevent temperatures inside and outsidethe sleeve 21 from mutually affecting each other when air enters. Inother embodiments, if both the first air inlet 2201 and the second airinlet 1301 are located at different positions, then the third aperture32 may be multiple in number to correspond to both the first air inlet2201 and the second air inlet 1301.

FIGS. 19A˜19C are perspective views of the power source 5 of oneembodiment at different viewpoints. FIG. 19D is a main view of the powersource 5 of one embodiment. The power source 5 is electrically connectedto the LED chips 311 to power the LED chips 311. As shown in FIGS.19A˜19C, the power source 5 includes a power board 51 and a plurality ofelectronic components mounted thereon.

As shown in FIG. 11, the power board 51 is parallel to the axis of theLED lamp. Thus, in the axial direction of the LED lamp, the power board51 is divided into an upper portion and a lower portion. Arrangingspaces of both the upper portion and the lower portion are identical orapproximately identical to form better layout of the electroniccomponents. Besides, if the power board 51 inclines toward the axis ofthe LED lamp, then air flow may be obstructed and it is disadvantageousto heat dissipation of the power source 5.

As shown in FIG. 11, the power board 51 divides an inner chamber of thelamp shell 2 into a first portion 201 and a second portion 202. Thefirst portion 201 is greater than the second portion 202 in volume. Whenimplementing layout of electronic components, most or all of electroniccomponents or some thereof which generate a large amount of heat such asinductors, resistors, transformers, rectifiers or transistors may bedisposed in the first portion 201.

As shown in FIG. 11, the electronic components 501 includeheat-generating elements 501. At least one of the heat-generatingelements 501 is adjacent to the lamp head 23 through which heat isdissipated without occupying resource of heat dissipation of the firstheat dissipating channel 7 a. The at least one heat-generating element501 abovementioned is an inductor, a resistor, a rectifier or a controlcircuit.

As shown in FIG. 11, heat of the at least one heat-generating element istransferred to the lamp head 23 through thermal conduction or radiationand dissipated to air through the lamp head 23.

As shown in FIG. 11, the at least one heat-generating element 501 is inthermal contact with the lamp head 23. In detail, the at least oneheat-generating element 501 is located in the lamp head 23. Theheat-generating element 501 is in contact with the lamp head 23 througha thermal conductor 53 and the heat-generating element 501 is fastenedto the lamp head 23 through the thermal conductor 53. Therefore, thethermal conductor not only performs an effect of heat transfer but alsofixes the heat-generating element 501 to avoid loosening of theheat-generating element 501. The phrase “the heat-generating element 501is located in the lamp head 23” means both the lamp head 23 and theheat-generating element 501 have an overlapping area in a projectionperpendicular to the axis of the LED lamp.

As shown in FIG. 11, the thermal conductor 53 is disposed in the lamphead 23 through filling to implement connection between the lamp head 23and the heat-generating element 501. The thermal conductor 53 onlycloaks an end portion of the power source 5 and is higher than theventing 222 in position to prevent overweight resulting from the thermalconductor 53. Additionally, the thermal conductor 53 adopts aninsulative material to guarantee safety and prevent the electroniccomponents and metal portion 231 of the lamp head 23 from being incontact. In other embodiments, the thermal conductor 53 may also be awire connecting the power source 5 to the lamp head 23 (not shown).

As shown in FIG. 11, the lamp head 23 includes the metal portion 231,which is in thermal contact with the thermal conductor 53. That is, atleast part of an inner side of the metal portion 231 constitutes a wallof the inner chamber of the lamp shell 2 to make the thermal conductordirectly connect with the metal portion 231 and perform heat dissipationby the metal portion 231. Part of the metal portion 231 would performheat dissipation through air, and another part of the metal portionwould perform heat dissipation through a lamp socket connecting to themetal portion 231.

As shown in FIGS. 2 and 19A, in this embodiment, at least one of theelectronic components of the power source 5, which is the most adjacentto the first air inlet 2201 of the first heat dissipating channel 7 a isa heat intolerance component, such as a capacitor, especially for anelectrolytic capacitor. This arrangement can avoid overheating of theheat intolerance component to affect its performance.

As shown in FIG. 19A, in this embodiment, at least part of at least oneof the electrolytic capacitors 502 is not located within the power board51, i.e. at least part of the electrolytic capacitor exceeds the powerboard 51 in the axial direction of the LED lamp. Under a condition ofthe same number of the electronic components, length and material costof the power board 51. In addition, this can make the electrolyticcapacitor further adjacent to the first air inlet 2201 to ensure theelectrolytic capacitor to be located in a relatively low temperaturearea.

As shown in FIG. 11, a position of at least one of the heat-generatingelements 501 in the axial direction of the LED lamp is higher than aposition of the venting hole 222. Most heat of the heat-generatingelement 501 higher than the venting hole 222 is dissipated through thelamp head 23 or other paths. Thus, most heat therefrom is not dissipatedthrough the venting hole 222, and convection speed of the first heatdissipating channel 7 a would not be affected. The heat-generatingelement is an IC, a transistor, a transformer, an inductor, a rectifieror a resistor.

As shown in FIG. 11, the power board 51 is divided into an upper partand a lower part in the axial direction of the LED lamp. Heat-generatingelements are arranged in both the upper part and the lower part. Atleast one of the heat-generating elements in the upper part is locatedabove the venting hole 222 to lower the temperature of the upper partnear the venting hole 222. This can increase an air temperaturedifference between two venting holes 222 in the upper part and the lowerpart to enhance convection.

As shown in FIGS. 2, 3 and 19A, when the power board 51 is assembled inthe lamp shell 2, it has a first portion in the lamp neck 22 and asecond portion in the sleeve 21. The second portion more adjacent to thefirst air inlet 2201 of the first heat dissipating channel 7 a than thefirst portion. Because of such an arrangement, convention air will reachthe second portion first. That is, the second portion is better than thefirst portion in an effect of heat dissipation. Thus, at least part ofheat intolerance elements (e.g. electrolytic capacitors or otherelements which is sensitive to high temperature) should be disposed inthe second portion. Preferably, all electrolytic capacitors are disposedin the second portion. The power board 51 of the second portion isgreater than the first portion in area, so the power board 51 of thesecond portion has more space for accommodating electronic components tobe advantageous to more heat intolerance elements being disposed in thesecond portion. In this embodiment, heat intoleranceelements/thermo-sensitive elements may be separately mounted on twoopposite sides of the second portion. In other embodiments, hotterelectronic components may be disposed in the second portion (e.g.transformers, inductors, resistors, ICs or transistors) for better heatdissipation.

As shown in FIGS. 1, 2, 3 and 4, the lamp shell 2 includes the lamp head23, the lamp neck 22 and the sleeve 21. The lamp head 23 connects to thelamp neck 22 which connects to the sleeve 21. The sleeve 21 is locatedin the heat sink 1 (in the axial direction of the LED lamp, all or mostof the sleeve 21, for example, at least 80% of height of the sleeve 21,does not exceed the heat sink 1). The lamp neck 22 projects from theheat sink 1. Both the sleeve 21 and the lamp neck 22 can providesufficient space to receive the power source 5 and perform heatdissipation, especially for the power source 5 of a high power LED lamp(in comparison with a low power LED lamp, a power source of a high powerLED lamp has more complicated composition and larger size). The powersource 5 is received in both the lamp neck 22 and lamp head 23. Totalheight of the lamp neck 22 and the lamp head 23 is greater than heightof the heat sink 1 so as to provide more space for receiving the powersource 5. The heat sink 1 is separate from both the lamp neck 22 and thelamp head 23 (not overlap in the axial direction, the sleeve 21 isreceived in the heat sink 1). Thus, the power source 5 in both the lampneck 22 and the lamp head 23 is affected by the heat sink 1 slightly(heat of the heat sink 1 would not be conducted to the lamp neck 22 andthe lamp head 23 along a radial direction). In addition, theconfiguration of height of the lamp neck 22 is advantageous to thechimney effect of the first heat dissipating channel 7 a to guaranteeconvection efficiency of the first heat dissipating channel 7 a. Inother embodiments, height of the lamp neck 22 is at least 80% of heightof the heat sink 1 to accomplish the above function. The sleeve 21 ismade of a thermo-isolated material to prevent mutual influence of heatfrom the fins and the power source.

As shown in FIG. 2, the second air inlet 1301 is located in a lowerportion of the heat sink 1 and radially corresponds to an inner side orthe inside of the heat sink 1, i.e. the second air inlet 1301 radiallycorresponds to the inner side or the inside of the fins 11. The innerside or the inside of the fins 11 corresponds to an outer wall (aradially inner side of the fins 11, which nears or abuts against thesleeve 21) of the sleeve 21 of the lamp shell 2. Thus, after convectionair flows into the second air inlet 1301, it flows upward along theouter wall of the sleeve 21 to perform convection and radiallydissipates heat in the inner side or the inside of the fins 11 and theouter wall of the sleeve 21 to implement an effect of thermal isolation.That is, this can prevent heat of the heat sink 1 is conducted from theouter wall of the sleeve 21 to the inside of the sleeve 21 not to affectthe power source 5. From the above, the second heat dissipating channel7 b can not only enhance heat dissipation of the fins 11, but alsoimplement an effect of thermal isolation. Make a positional comparisonbetween the second air inlet 1301 and the LED chips 311, the second airinlet 1301 is located radially inside all of the LED chips 311.

FIG. 20 is an enlarged view of portion B in FIG. 2. As shown in FIG. 20,the lamp head 23 includes a metal portion 231 and an insulative portion232. Wires of the power source 5 penetrates through the insulativeportion 232 to connect with an external power supply. The metal portion231 connects to the lamp neck 22. In detail, as shown in FIG. 21, aninner surface of the metal portion 231 is provided with a thread throughwhich the lamp neck 22 can be screwed on with the metal portion 231.While the metal portion 231 is dissipating heat generated from the powersource 5 in the lamp shell 2 (as described in the above embodiment, atleast part of the inner wall of the metal portion 231 forms a wall ofthe inner chamber of the lamp shell 2, so the thermal conductor directlyconnects with the metal portion 231 and the metal portion 231 can beused for heat dissipation), an outer surface of the metal portion 231 isformed with a projecting structure 2311 as shown in FIG. 21 to addsurface area of the outer surface of the metal portion 231 and enlargeheat dissipating area of the metal portion 231 to increase efficiency ofheat dissipation. As for the power source 5, at least part of the powersource 5 is located in the lamp head 23, and at least part of heatgenerated from the power source 5 can be dissipated through the lamphead 23. The inner wall of the metal portion 231 may also be formed witha projecting structure to add surface area of the inner chamber of thelamp shell 2. In this embodiment, the projecting structure can beimplemented by forming a thread on the inner surface of the metalportion 231.

As shown in FIGS. 1 and 18, the lamp shell 2 has an airflow limitingsurface 214 which extends radially outwardly and is located away fromthe venting hole 222. The airflow limiting surface 214 cloaks at leastpart of the fins 11. When the fins are dissipating heat, hot airflowheated by the part of fins 111 cloaked by the airflow limiting surface214 rises but is blocked by the airflow stopping surface 214 to changeits direction (outward along the airflow stopping surface 214). Thus,rising hot airflow is forced to go away from the venting hole 222. Thiscan prevent hot air from both gathering around the venting hole 222 andaffecting convection speed of the first heat dissipating channel 7 a.Also, this arrangement can prevent rising hot air from both being incontact with the metal portion 231 of the lamp head 23 and affectingheat dissipation of the metal portion 231. Even hot air directly passingthe metal portion 231 to conduct into the inner chamber of the lampshell 2 can also be avoided. The airflow stopping surface 214 may beformed on the sleeve 21. As shown in FIG. 7, in another embodiment ofthe present invention, the airflow stopping surface 214 may also beformed on the lamp neck 22.

As shown in FIG. 18, in this embodiment, upper portions of at least partof the fins 11 in the axial direction of the LED lamp correspond to theairflow stopping surface 214. When the lamp shell 2 is inserted into theheat sink 1, the airflow stopping surface 214 will have a limitingeffect to the lamp shell 2. In this embodiment, the fins abut againstthe airflow stopping surface 214.

As shown in FIG. 18, in this embodiment, both a wall of the sleeve 21and a wall of the lamp neck 22 jointly constitute a wall of the innerchamber of the lamp shell 2. Height of the heat sink 1 in the axialdirection does not exceed height of the sleeve 21 to make the heat sink1 corresponds to the sleeve 21 in a radial direction of the LED lamp.That is, the sleeve 21 has an effect of thermal isolation to preventheat of the heat sink 1 from being conducted to the sleeve 21, so thatelectronic components of the power source 5 world not be affected. Allthe lamp neck 22 is higher than a position of the heat sink 1. That is,in a radial direction of the LED lamp, the heat sink 1 does not overlapthe lamp neck 22. This can make thermal conduction between the heat sink1 and the lamp neck 22,and prevent heat from the heat sink 1 to conductto the inside of the lamp neck 22, so that the electronic componentstherein would not be affected. As a result, in this embodiment, heatconducting efficiency of the wall of the sleeve 21 is configured to belower than heat conducting efficiency of the wall of the lamp neck 22.Advantages of such configuration are as follows: (1) because heatconducting efficiency of the sleeve 21 is relatively low, thermalconduction from the heat sink 1 to the sleeve 21 can be reduced toprevent electronic components in the sleeve 21 form being affected bythe heat sink 1; and (2) because thermal conducting from the heat sink 1to the lamp neck 22 does not need to be considered, heat conductingefficiency of the lamp neck 22 can be increased to be advantageous todissipating heat from the electronic components of the power source 5through the lamp neck 22. This can avoid life shortening of the powersource 5 due to overheating. In this embodiment, in order to make heatconducting efficiency of the wall of the sleeve 21 be lower than heatconducting efficiency of the wall of the lamp neck 22, the sleeve 21 ismade of a material with low thermal conductivity and the lamp neck 22 ismade of a material with relatively high thermal conductivity. Toincrease thermal conductivity of the lamp neck 22, the lamp neck 22 maybe provided with a venting hole 222 or a heat conducting portion (notshown) such as metal or other materials with high thermal conductivity.

As shown in FIG. 18, the lamp neck 22 has an upper portion and a lowerportion. The venting hole 222 is located in the upper portion.Cross-sectional area of the upper portion is less than cross-sectionalarea of the lower portion. Airflow speed in the upper portion is fasterthan that in the lower portion, so that initial speed of air ejectedfrom the venting hole 222 can be increased to prevent hot air fromgathering around the venting hole 222. In this embodiment,cross-sectional area of the lamp neck 22 upward tapers off in the axialdirection to avoid obstruction to air flowing. In this embodiment,cross-sectional area of an inlet of the lower portion of the sleeve 21is greater than that of the upper portion of the lamp neck 22.

As shown in FIG. 1, the venting hole 222 of the lamp neck 22 is of astrip shape and extends along the axial direction of the LED lamp.Because of gravity of the LED lamp itself, the lamp neck 22 would sufferan axial pulling force. The venting hole 222 are configured to be of astrip shape extending the axial direction of the LED lamp, so stressconcentration caused by the venting hole 222 in the lamp neck 22 can beprevented. A maximum diameter of an inscribed circle of the venting hole222 is less than 2 mm, preferably, between 1 mm and 1.9 mm. As a result,the venting hole 222 can prevent bugs from entering and prevent mostdust from passing. On the other hand, the vent 41 can keep betterefficiency of air flowing. On the other hand, if the venting hole 222 isconfigured to annular extending along an circumferential portion of thelamp neck 22, then the lamp neck 22 may be deformed by weight of theheat sink 1 to make the venting hole 222 become larger. This would causethat a maximum diameter of an inscribed circle of the venting hole 222is greater than 2 mm, this cannot satisfy the requirement.

As shown in FIG. 10, the venting hole 222 is outside an outer surface ofthe metal portion 231 in radial directions. This can reduce influence tothe metal portion 231 because of rising air ejected from the ventinghole 222 and prevent heat from being conducted back to the lamp shell 2.

FIG. 22 is a cross-sectional view of the LED lamp of another embodiment.FIG. 23 is a schematic view of arrangement of the convection channels inthe LED lamp. As shown in FIGS. 22 and 23, in some embodiments, afundamental structure of the LED lamp is identical to the LED lamp shownin FIG. 1. In some embodiments, the sleeve 21 has an upper portion and alower portion. The upper portion is connected to the lower portionthrough an air guiding surface 216. A diameter of cross-section of theair guiding surface 216 downward tapers off along the axis of the LEDlamp (along the convection direction of the first heat dissipatingchannel 7 a). That is, the air guiding surface 216 can guide air in thesecond heat dissipating channel 7 b toward the radial outside of theheat sink 1 so as to make air be in contact with more area of the fins11 to bring out more heat of the fins 11. The sleeve 21 includes a firstportion and a second portion in the axial direction. The second portionis a part of the sleeve 21 below the air guiding surface 216 (includingthe air guiding surface 216). The first portion is the other part of thesleeve 21 above the air guiding surface 216 (but not including the airguiding surface 216). Electronic components of the power source 5, whichare located in the second portion of the sleeve 21, include heatintolerance elements such as capacitors, especially electrolyticcapacitors so as to make the heat intolerance elements work in lowtemperature environment (near the first air inlet 2201). In otherembodiments, high heat-generating elements may be disposed in the secondportion of the sleeve 21, such as resistors, inductors and transformers.As for the second heat dissipating channel 7 b, when convection airflows into the second heat dissipating channel 7 b and reaches the lowerportion of the sleeve 21, the convection air would lean against theouter wall of the sleeve 21 to rise. This can generate an effect ofthermal isolation, i.e. heat of the fins 11 is prevented from beingconducted to the inside of the sleeve 21 so that the heat intoleranceelements therein would not be affected. When the convection aircontinues to rise, the convection air will flow outward along radialdirections of the fins 11 under the guide of the air guiding surface 216so as to make the convection air be in contact with more area of thefins 11 to enhance an effect of heat dissipation of the fins 11. In thisembodiment, the inner chamber of the sleeve 21 is of awide-upper-side-and-narrow-lower-side channel structure. Thissignificantly enhances the chimney effect and promotes air flowing inthe sleeve 21. In addition, the venting hole 222 can be designed on thelamp neck 22 away from the vent to further improve the chimney effect.

As shown in FIGS. 24 to 32, the present disclosure provides a powersupply module for LED lamp. The power supply module includes input ends(ACN, ACL) for receiving AC driving signal; a first rectifying circuit100 for converting the AC driving signal into rectified signal; afiltering 200 for converting the rectified signal into filtered signal;a power converter 400 for converting the filtered signals into powersignal which is capable of lighting up an LED light source 500; and abias generating circuit 600 electrically connected to the input ends(ACN, ACL) and the power converter 400 for performing buck-conversion tothe AC driving signal to generate a working voltage of the powerconverter 400.

In this embodiment, the first rectifying circuit 100 may be a bridgerectifier. As shown in FIG. 26, which is a circuit diagram of arectifying circuit and a filtering circuit of an embodiment of theinvention, the first rectifying circuit 100 includes diodes D7, D8, D9and D10. The first rectifying circuit 100 performs full waverectification to the AC driving signal to generate DC driving signal (DCpower).

In detail, as shown in FIG. 26, anodes of diodes D7, D9 are electricallyconnected to a first end of the filtering circuit 200, cathodes ofdiodes D7, D9 are electrically connected to anodes of diodes D8, D10,and cathodes of diodes D8, D10 are electrically connected to a secondend of the filtering circuit 200. Contacts of diodes D7 and D8 areelectrically connected to the first end ACL. A cathode of diode D8 iselectrically connected to a cathode of diode D10. Contacts of diodes D9and D10 are electrically connected to the second end ACN.

In this embodiment, the filtering circuit 200 includes capacitors C1, C2and an inductor L1. First ends of both capacitor C1 and inductor L1serve as the second end of the filtering circuit 200 to electricallyconnect with cathodes of diodes D8 and D10. The second end of inductorL1 is electrically connected to the first end of capacitor C1. Thesecond ends of capacitors C1 and C2 serve as the first end of thefiltering circuit 200 to electrically connect with anodes of diodes D7and D9. The filtering circuit 200 receives the DC power (the rectifiedsignal) rectified by the first rectifying circuit 100 and filters highfrequency components of the DC power.

An electro-magnetic interference (EMI) reduction circuit 900 may bedisposed between the input ends (ACN, ACL) and the rectifying circuit100. The EMI reduction circuit 900 can reduce influence to the drivingsignal from an interference magnetic field.

In addition, the branch electrically connected to the input ends ACN,ACL may further be connected with a fuse F1 in series. The fuse F1 maybe a current fuse or a temperature fuse.

FIG. 28 is a circuit diagram of a power converter of an embodiment ofthe invention. As shown in FIGS. 24 and 28, the power converter 400receives signal from a pre-stage circuit through the connecting end 401,402, and the power signal are provided to a post-stage through theconnecting ends 5001, 5002. The power converter 400 may adopt a PWM(Pulse Width Modulation) circuit, which controls pulse width to outputtarget signal. In detail, the power converter 400 includes a controllerU2, a power switch Q2, a transformer T2 and a diode D10. To reduce bothinfluence resulting from harmonic to circuit properties and conversionloss, a power factor correction (PFC) circuit 300 may be disposedbetween the power converter 400 and filtering circuit 200. The PFCcircuit 300 can increase power factors of the filtered signal byadjusting signal properties (e.g. phase, level or frequency) of thefiltered signal. PFC circuit 300 electrically connects to an output endof bias generating circuit 600. In detail, PFC circuit 300 may be anactive PFC circuit.

FIG. 27 is a circuit diagram of a PFC circuit of an embodiment of theinvention. As shown in FIG. 27, PFC circuit 300 receives signal from thefiltering circuit 300 through the connecting ends 301, 302 and sendscorrected signal to the post-stage power converter 400 throughconnecting ends 401, 402. PFC circuit 300 includes a controller U1, apower switch Q1 electrically connected to controller U1, a transformerT1 and a diode D3. Power switch Q1 may be a MOSFET. A first end (powerend) of the controller U1 electrically connects to an output end 607 ofbias generating circuit 600. A second end of controller U1 electricallyconnects to an end of transformer T1. A coil of transformer T1electrically connects to a main branch in series. The other end of thecoil electrically connected to a second end of controller U1 isgrounded. A positive end (also called connecting end 5001) of the DCoutput ends electrically connects to the main branch. Diode D3 iselectrically connected in the branch in series. An anode of diode D3electrically connects to both an end of transformer T1 and the filteringcircuit 200, and a cathode thereof electrically connects to connectingend 401 for electrically connecting to both power converter 400 andconnecting end 5001. A third end of controller U1 electrically connectsto power switch Q1. An end of power switch Q1 electrically connects to afifth electrically connecting point between diode D3 and transformer T1.Controller U1 may further electrically connects to a sampling circuit (aconnecting point between resistor R2 and capacitor C3 electricallyconnects to the controller U1, and capacitor C3 electrically connects toresistor R3 in parallel) and other circuits as shown in FIG. 27.

FIG. 29 is a circuit diagram of a bias generating circuit of the firstembodiment of the invention. As shown in FIGS. 25 and 29, biasgenerating circuit 600 a may include an electricity obtainer 610, aswitch controller U3 and an energy storage flyback unit 630. Electricityobtainer 610 electrically connects to both the input ends (ACN, ACL) andswitch controller U3. Switch controller U3 electrically connects toenergy storage unit 630 having an output end 607 for outputting aworking voltage (VCC). Output end 607 electrically connects to powerconverter 400 to provide the working voltage (VCC) to the powerconverter 400.

In an embodiment, the electricity obtainer 610 can convert AC drivingsignal into DC electricity obtaining signal which are equal to the ACdriving signal. As shown in FIGS. 25 and 29, electricity obtainer 610can be implemented by a second rectifying circuit (hereinafter “secondrectifying circuit 610”). Second rectifying circuit 610 includes a firstdiode D1 and a second diode D2, which are electrically connected inseries with opposite polarity (i.e. cathodes of diodes D1 and D2 areelectrically connected together). Second rectifying circuit 610 has anelectricity obtaining end 601 between diodes D1 and D2. The electricityobtaining end 601 electrically connects to the switch controller U3. Bythe opposite polarity, the two diodes D1 and D2 rectify the AC drivingsignal to output DC driving signal at the electricity obtaining end 601.

In detail, the electricity obtaining end 601 further electricallyconnects to an end of first capacitor C9, and the other end thereofelectrically connects to the ground end GND. Switch controller U3electrically connects to an end of inductor L2, and the other endthereof connects to the output end 607. Inductor L2 can perform bothenergy storage and release and maintain the current continuity whenswitch controller U3 is switching.

In this embodiment, energy storage flyback unit 630 may include aninductor L2, a third diode D5 and a second capacitor C11. A cathode ofthe third diode D5 connects to a connecting end 603 disposed between theswitch controller U3 and inductor L2. An anode of third diode D5connects to ground end GND. An end of second capacitor C11 electricallyconnects to a second connecting end 604 disposed between inductor L2 andthe output end 607. The other end of second capacitor C11 electricallyconnects to the ground end GND. an end of a load resistor electricallyconnects to a third connecting end (not shown in FIG. 25) disposedbetween the second connecting end 604 and the output end 607. The otherend of the load resistor electrically connects to ground end GND.

The bias generating circuit 600 may be further provided with a samplingcircuit to sample its working status and to be a reference of outputsignal of the switch controller. In addition, in the practicalapplication, switch controller U3 may be a chip or IC integrated with atleast a control circuit and a power switch, but the present invention isnot limited thereto.

For example, the sampling circuit may include a first sampling circuit650 and a second sampling circuit 620. First sampling circuit 650electrically connects to both the electricity obtaining end 601 (forminga connecting point 605 in FIG. 29) and switch controller U3. The secondsampling circuit 620 electrically connects to both the output end 607and switch controller U3. Switch controller U3 outputs a stable workingvoltage according to sampling signal from both the first samplingcircuit 650 and second sampling circuit 620. Configuration of thesampling circuit is related to the control manner of switch controllerU3, the invention is not limited to this. FIG. 29 is a circuit diagramof the bias generating circuit of the first embodiment of the invention.

In other embodiments, the bias generating circuit may also be used forproviding a working voltage to a temperature sensing circuit 700. FIG.30 is a circuit diagram of the bias generating circuit of the secondembodiment of the invention. FIG. 31 is a circuit diagram of atemperature sensing circuit of an embodiment of the invention. As shownin FIGS. 30 and 31, the temperature sensing circuit 700 electricallyconnects to power converter 400 for sending temperature detecting signalto power converter 400. The temperature sensing circuit 700 has atemperature sensor electrically connecting to bias generating circuit600 b to make bias generating circuit 600 b provide a working voltage totemperature sensing circuit 600 b.

In this embodiment, in comparison with the embodiment shown in FIG. 29,the bias generating circuit 600 b of this embodiment further includes atransistor Q3, a diode D6, a resistor R12 and a capacitor C10.Transistor Q3 may be a BJT as an example (hereinafter refer as BJT Q3).The temperature detector 700 electrically connects to BJT Q3 of the biasgenerating circuit 600 b. The collector of BJT Q3 electrically connectsto output end 607. The base of BJT Q3 electrically connects to thegrounding line with the ground end GND.

Moreover, as shown in FIG. 32, the temperature sensing circuit 700further electrically connects to a temperature compensator 800. FIG. 32is circuit diagram of a temperature compensator of an embodiment of theinvention. Temperature sensing circuit 700 electrically connects betweentemperature compensator 800 and bias generating circuit 600 b.Temperature compensator 800 electrically connects to power converter400.

The output end of the temperature compensator 800 electrically connectsto the controller U2 of the power converter 400 to make the temperaturesensing result signal Vtemp fed back to controller U2 of power converter400, so that controller U2 can adjust the output power depending on thesystem environment temperature.

In detail, a circuit diagram of the temperature compensator 800 may beas shown in FIG. 32. It should be noted that, the temperaturecompensator 800 can be implemented by various manners. The invention isnot limited to the circuit shown in FIG. 32.

The invention further provides a high power LED lamp including an LEDlight source 500 and a power supply module as abovementioned connectingwith the LED light source 500. In some embodiments, the high power LEDlamp means all types of LED lamps whose output power exceeds 30 w, LEDlamps which are equivalent to xenon lamps with output power of at least30 W or LED lamps using high power lamp beads (e.g. lamp beads withrated current above 20 mA).

The above depiction has been described with reference to theaccompanying drawings, in which exemplary embodiments of the disclosureare shown. This disclosure may, however, be embodied in many differentforms and should not be construed as limited to the embodiments setforth herein. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art.

What is claimed is:
 1. An LED (light emitting diode) lamp comprising: alamp shell including a lamp head, a lamp neck and a sleeve, the lamphead connects to the lamp neck which connects to the sleeve; a passiveheat dissipating element having a heat sink connected to the lamp shell,wherein the heat sink comprises fins and a base, the sleeve of the lampshell is located in the heat sink, the lamp neck projects from the heatsink, height of the lamp neck is at least 80% of height of the heatsink, the heat sink comprises first fins and second fins, bottoms ofboth the first fins and the second fins in an axis of the LED lampconnect to the base, the first fins interlace with the second fins atregular intervals, and one of the second fins includes a third portionand two fourth portions, the two fourth portions are symmetrical aboutthe third portion; a power source having a first portion and a secondportion, wherein the first portion of the power source is disposed inboth the lamp neck and the lamp head of the lamp shell, and the secondportion of the power source is disposed in the heat sink of the passiveheat dissipating element; a light emitting surface connected to the heatsink of the passive heat dissipating element and comprising LED chipselectrically connected to the power source, wherein the light emittingsurface and the heat sink are connected to form a heat transferring pathfrom the LED chips to the passive heat dissipating element; a first heatdissipating channel formed in a chamber of the lamp shell fordissipating heat generated from the power source while the LED lamp isworking, and the chamber is located between the bottom of the LED lampand the upper portion of the lamp neck; a second heat dissipatingchannel formed in the heat sink and between the fins and the base fordissipating the heat generated from the LED chips and transferred to theheat sink; and a lamp cover connected with the heat sink and having alight output surface and an end surface, wherein the end surface isformed with a vent to let air flowing from outside of the LED lamp intoboth the first heat dissipating channel and the second heat dissipatingchannel through the vent; wherein the first heat dissipating channelcomprises a first end on the light emitting surface to allow air flowingfrom outside of the LED lamp into the chamber, and a second end on theupper portion of the lamp neck of the lamp shell to allow air flowingfrom inside of the chamber out to the LED lamp; wherein the second heatdissipating channel comprises a third end on the light emitting surfaceto allow air flowing from outside of the LED lamp into the second heatdissipating channel, and flowing out from spaces between every adjacenttwo of the fins; wherein the light emitting surface further comprises anaperture configured to simultaneously communicate with both the firstend of the first heat dissipating channel and the third end of thesecond heat dissipating channel, the aperture is located in a centralregion of the light emitting, and the aperture forms an air intake ofboth the first heat dissipating channel and the second heat dissipatingchannel; wherein the heat sink is disposed outwardly of the sleeve, andthe second portion of the power source is disposed in the inner space ofthe sleeve, the second portion of the power source and the heat sink ofthe passive heat dissipating element are insulated through the sleeve toprevent heat from the heat sink from affecting the power source in thesleeve; wherein the first end is projected onto the end surface in anaxis of the LED lamp to occupy an area on the end surface, which isdefined as a first portion, another area on the end surface is definedas a second portion, and the vent in the first portion is greater thanthe vent in the second portion in area.
 2. The LED lamp of claim 1,wherein a distance is kept between distal ends of the fins and thesleeve, and air exists in the distance between the fins and the sleeveof the lamp shell.
 3. The LED lamp of claim 1, wherein part of the finsare in contact with an outer surface of the sleeve.
 4. The LED lamp ofclaim 2, wherein the first end on the light emitting surface is formedwith an air inlet, the air inlet is located in a lower portion of theheat sink and radially corresponds to an inner side or the inside of theheat sink.
 5. The LED lamp of claim 4, wherein the sleeve has an upperportion and a lower portion, the upper portion is connected to the lowerportion through an air guiding surface, a diameter of cross-section ofthe air guiding surface downward tapers off along the axis of the LEDlamp.
 6. The LED lamp of claim 5, wherein the sleeve includes a firstportion and a second portion in the axial direction, the second portionis a part of the sleeve below the air guiding surface, electroniccomponents of the power source, which are located in the second portionof the sleeve, include electrolytic capacitors.
 7. The LED lamp of claim6, wherein the second end on the upper portion of the lamp neck of thelamp shell is formed with a venting hole, the lamp shell has an airflowlimiting surface which extends radially outwardly and is located awayfrom the venting hole, the airflow limiting surface cloaks at least partof the fins.
 8. The LED lamp of claim 7, wherein upper portions of atleast part of the fins in the axial direction of the LED lamp correspondto the airflow limiting surface.
 9. The LED lamp of claim 8, wherein anouter wall of the sleeve is provided with a passage to make part ofconvection air pass through the passage to reach the heat sink.
 10. TheLED lamp of claim 9, wherein the power source includes a heat-generatingelement, the heat-generating element is in contact with the lamp headthrough a thermal conductor and the heat-generating element is fastenedto the lamp head through the thermal conductor.
 11. The LED lamp ofclaim 10, wherein the lamp head includes a metal portion, at least partof an inner side of the metal portion constitutes a wall of the innerchamber of the lamp shell to make the thermal conductor directlyconnecting with the metal portion and performing heat dissipation by themetal portion.
 12. The LED lamp of claim 11, wherein all theelectrolytic capacitors are disposed in the sleeve.
 13. The LED lamp ofclaim 12, wherein at least one of the electronic components of the powersource, which is the most adjacent to the first end of the first heatdissipating channel is one of the electrolytic capacitor.
 14. The LEDlamp of claim 13, wherein at least part of the electrolytic capacitorwhich is the most adjacent to the first end of the first heatdissipating channel exceeds the power board in the axial direction ofthe LED lamp.